White Yeti
National Hazard
Posts: 816
Registered: 20-7-2011
Location: Asperger's spectrum
Member Is Offline
Mood: delocalized
|
|
What have I created.
Pardon the length of this post, I wanted to make it as detailed as possible.
So I recently tried to make some sodium sulphite and bisulphite and I must say that the synthesis was nothing short of a disaster.
I burned sulphur and collected the SO2 in a bottle that I subsequently filled with about 20mL of a saturated sodium carbonate solution. I closed the
bottle and shook it to get the SO2 to dissolve and react with the carbonate.
I made some SO2 by burning sulphur in a small spoon made of aluminium foil. I accidentally dropped the spoon into the bottle and didn't bother trying
to get it back. At the end of the synthesis, I got a small 20mL sample of what should be sodium bisulphite and sulphite, massively contaminated with
colloidal sulphur, sodium carbonate and sodium bicarbonate.
I filtered the mixture, the colloidal sulphur was small enough to pass through the filter. I eventually retrieved the aluminium foil spoon and set it
down to dry. Large white crystals began to form on the spoon, but a streak of bright yellow crystals began to appear on one particular area on the
spoon.
I deduced that if I made any sulphur compound whatsoever, I would get the smell of SO2 if I poured acid on the crystals.
I didn't want to use HCl because that would react with Al, so used vinegar instead.
I ran into quite a surprise, as soon as I poured the acid onto the crystals, I got the overwhelming smell of H2S!
I tried the same thing on the batch of aqueous "sulphite" and I got nothing at all, not even SO2 or CO2 (from the carbonate).
I'm fine now, that whiff of H2S scared the wits out of me. Thankfully I was working with micro scale quantities.
Does anyone know what might have happened? Did any sulphite react with aluminium to form a sulphide of some kind?
Thanks for reading.
"Ja, Kalzium, das ist alles!" -Otto Loewi
|
|
|
Adas
National Hazard
Posts: 711
Registered: 21-9-2011
Location: Slovakia
Member Is Offline
Mood: Sensitive to shock and friction
|
|
Aluminium react with sulfur to form Al2S3, which releases H2S upon contact with water. The vinegar probably released the H2S from Na2S, which might
have been also formed, when the H2S from Al2S3 reacted with the solution.
Be careful with H2S.
|
|
|
mr.crow
National Hazard
Posts: 884
Registered: 9-9-2009
Location: Canada
Member Is Offline
Mood: 0xFF
|
|
Its possible you made sodium thiosulfate from sulfur and sulfite, that make large white crystals. Adding acid will make SO2 and S
Does iron or aluminum react with sulfur in solution? With base? Usually you have to ignite a Fe/S solid mixture
Double, double toil and trouble; Fire burn, and caldron bubble
|
|
|
Adas
National Hazard
Posts: 711
Registered: 21-9-2011
Location: Slovakia
Member Is Offline
Mood: Sensitive to shock and friction
|
|
Quote: Originally posted by mr.crow  | | Does iron or aluminum react with sulfur in solution? With base? Usually you have to ignite a Fe/S solid mixture |
He said he was heating sulfur on Al foil.
|
|
|
White Yeti
National Hazard
Posts: 816
Registered: 20-7-2011
Location: Asperger's spectrum
Member Is Offline
Mood: delocalized
|
|
Yes, but from previous experience, very high temperatures are needed to initiate the reaction. It's plausible but sulphur doesn't burn nearly as hot
as it should to initiate a reaction with aluminium.
"Ja, Kalzium, das ist alles!" -Otto Loewi
|
|
|
Adas
National Hazard
Posts: 711
Registered: 21-9-2011
Location: Slovakia
Member Is Offline
Mood: Sensitive to shock and friction
|
|
But why the H2S smell then?
|
|
|
Random
International Hazard
Posts: 1120
Registered: 7-5-2010
Location: In ur closet
Member Is Offline
Mood: Energetic
|
|
Maybe just the small amounts of aluminium sulphide formed, as H2S is detectable in very small concentrations. High concentrations, your sense of smell
will be disabled.
|
|
|
mr.crow
National Hazard
Posts: 884
Registered: 9-9-2009
Location: Canada
Member Is Offline
Mood: 0xFF
|
|
On a related note, once I discovered an interesting reaction.
I put a solution of sodium nitrate and sodium hydroxide on a piece of aluminum foil. Then I applied a flame from a butane torch. A reaction spread on
the surface of the aluminum like fire, burning a hole through it and producing a strong smell of ammonia.
So the aluminum was activated by the strong base and heat, which reduced the nitrate to ammonia. Maybe something similar happened with your sulfur
experiment.
Double, double toil and trouble; Fire burn, and caldron bubble
|
|
|
Adas
National Hazard
Posts: 711
Registered: 21-9-2011
Location: Slovakia
Member Is Offline
Mood: Sensitive to shock and friction
|
|
| Quote: Originally posted by mr.crow | On a related note, once I discovered an interesting reaction.
I put a solution of sodium nitrate and sodium hydroxide on a piece of aluminum foil. Then I applied a flame from a butane torch. A reaction spread on
the surface of the aluminum like fire, burning a hole through it and producing a strong smell of ammonia.
So the aluminum was activated by the strong base and heat, which reduced the nitrate to ammonia. Maybe something similar happened with your sulfur
experiment. |
??? How can be nitrate reduced to ammonia? Can you write an equation? (I must try this experiment one day)
|
|
|
theflickkk
Harmless
Posts: 33
Registered: 29-3-2011
Member Is Offline
Mood: No Mood
|
|
It's used to test for the presence of nitrates. Kinda like devarda's alloy but it works with either aluminium or zinc too.
|
|
|
![[*]](images/xpblue/default_icon.gif){kind=icon}
